// Copyright 2017 JanusGraph Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.janusgraph.diskstorage.configuration;

import java.io.Closeable;
import java.util.Collections;

/**
 * @author Matthias Broecheler (me@matthiasb.com)
 */
public interface ReadConfiguration extends Closeable {

    ReadConfiguration EMPTY = new ReadConfiguration() {
        @Override
        public<O> O get(String key, Class<O> datatype) {
            return null;
        }

        @Override
        public Iterable<String> getKeys(String prefix) {
            return Collections.emptyList();
        }

        @Override
        public void close() {
            //Nothing
        }
    };

    <O> O get(String key, Class<O> datatype);

    Iterable<String> getKeys(String prefix);

    @Override
    void close();

}
